Ooh, Sonic Mania! Haven't played that one yet, although I want to.
But anyway, I did my Sonic 2 run. For a long time, I was never a big fan of the special stages in this one, compared to Sonic 1 and Sonic 3 where I enjoyed them a lot more. However, I realize in Sonic 2 it was mostly because I would always play with both Sonic & Tails. Which normally I like having Tails along for the main game, but then whenever you do the special stages, the AI-controlled Tails keeps crashing into bombs and losing rings and making a nuisance of himself.

So more often than not I would end up just skipping the special stages entirely and not even bothering with the Chaos Emeralds.
But this time around, I decided I would give the special stages another chance. And I even learned recently that, if Tails in the special stages wasn't already frustrating enough, it even increases the total ring quota needed. So ultimately, I did my playthrough as Sonic by himself. Sorry Tails!

But don't worry; you'll get to join in on the next adventure!
The special stages were definitely better than I remembered, but still pretty hard! Or maybe I just haven't had enough time practicing with them compared to the other games. I only got 3 of the 7 emeralds. Total high score was
361,050.
I then did a second playthrough, this time as "Knuckles in Sonic 2". As much as I always thought the lock-on alternate modes were a cool gameplay feature, I seldom ever played Knuckles in Sonic 2 in the past; normally when I'd play Sonic 2 I'd just do the normal mode with Sonic. But part of the appeal in the Knuckles version is not only his unique gliding and climbing, but it also lowers the special stage ring quota even further, and he retains his total rings after returning from a special stage instead of going back to 0, which I thought might help me this time if I was going to try collecting the emeralds again.
Still pretty tough, however! I got 4 of 7 emeralds. Total high score
400,260.